Therefore as the word Shepherd and Pastor are interchangeable the Psalm 23 can be translate in this way:
Psalm

23:1 [A Psalm of David.] The
LORD is my shepherd; I shall not want.

23:1 [A Psalm of David.] The
LORD is my pastor; I shall not want.

Moreover in John 10 the word shepherd (pastor) refer to the Lord Jesus Christ.

All this argument is well summarize in
Ezekiel 34

34:1 And the word of the LORD came unto me, saying,

34:2 Son of man, prophesy against the shepherds of
Israel, prophesy, and say unto them, Thus saith the Lord GOD unto
the shepherds; Woe be to the shepherds of Israel that do feed
themselves! should not the shepherds feed the flocks?

34:3 Ye eat the fat, and ye clothe you with the
wool, ye kill them that are fed: but ye feed not the flock.

34:4 The diseased have ye not strengthened, neither
have ye healed that which was sick, neither have ye bound up that
which was broken, neither have ye brought again that which was
driven away, neither have ye sought that which was lost; but with
force and with cruelty have ye ruled them.

34:5 And they were scattered, because there is no
shepherd: and they became meat to all the beasts of the field,
when they were scattered.

34:6 My sheep wandered through all the mountains,
and upon every high hill: yea, my flock was scattered upon all the
face of the earth, and none did search or seek after them.

34:7 Therefore, ye shepherds, hear the word of the
LORD;

34:8 As I live, saith the Lord GOD, surely because
my flock became a prey, and my flock became meat to every beast of
the field, because there was no shepherd, neither did my shepherds
search for my flock, but the shepherds fed themselves, and fed not
my flock;

34:9 Therefore, O ye shepherds, hear the word of the
LORD;

34:10 Thus saith the Lord GOD; Behold, I am against
the shepherds; and I will require my flock at their hand, and
cause them to cease from feeding the flock; neither shall the
shepherds feed themselves any more; for I will deliver my flock
from their mouth, that they may not be meat for them.

34:11 For thus saith the Lord GOD; Behold, I, even
I, will both search my sheep, and seek them out.

34:12 As a shepherd seeketh out his flock in the day
that he is among his sheep that are scattered; so will I seek out
my sheep, and will deliver them out of all places where they have
been scattered in the cloudy and dark day.

34:13 And I will bring them out from the people, and
gather them from the countries, and will bring them to their own
land, and feed them upon the mountains of Israel by the rivers,
and in all the inhabited places of the country.

34:14 I will feed them in a good pasture, and upon
the high mountains of Israel shall their fold be: there shall they
lie in a good fold, and in a fat pasture shall they feed upon the
mountains of Israel.

34:15 I will feed my flock, and I will cause them to
lie down, saith the Lord GOD.

34:16 I will seek that which was lost, and bring
again that which was driven away, and will bind up that which was
broken, and will strengthen that which was sick: but I will
destroy the fat and the strong; I will feed them with judgment.

34:17 And as for you, O my flock, thus saith the
Lord GOD; Behold, I judge between cattle and cattle, between the
rams and the he goats.

34:18 Seemeth it a small thing unto you to have
eaten up the good pasture, but ye must tread down with your feet
the residue of your pastures? and to have drunk of the deep
waters, but ye must foul the residue with your feet?

34:19 And as for my flock, they eat that which ye
have trodden with your feet; and they drink that which ye have
fouled with your feet.

34:20 Therefore thus saith the Lord GOD unto them;
Behold, I, even I, will judge between the fat cattle and between
the lean cattle.

34:21 Because ye have thrust with side and with
shoulder, and pushed all the diseased with your horns, till ye
have scattered them abroad;

34:22 Therefore will I save my flock, and they shall
no more be a prey; and I will judge between cattle and cattle.

34:23 And I will set up one shepherd over them, and
he shall feed them, even my servant David; he shall feed them, and
he shall be their shepherd.

34:24 And I the LORD will be their God, and my
servant David a prince among them; I the LORD have spoken it.

34:25 And I will make with them a covenant of peace,
and will cause the evil beasts to cease out of the land: and they
shall dwell safely in the wilderness, and sleep in the woods *.

34:26 And I will make them and the places round
about my hill a blessing; and I will cause the shower to come down
in his season; there shall be showers of blessing.

34:27 And the tree of the field shall yield her
fruit, and the earth shall yield her increase, and they shall be
safe in their land, and shall know that I am the LORD, when I have
broken the bands of their yoke, and delivered them out of the hand
of those that served themselves of them.

34:28 And they shall no more be a prey to the
heathen, neither shall the beast of the land devour them; but they
shall dwell safely, and none shall make them afraid.

34:29 And I will raise up for them a plant of
renown, and they shall be no more consumed with hunger in the
land, neither bear the shame of the heathen any more.

34:30 Thus shall they know that I the LORD their God
am with them, and that they, even the house of Israel, are my
people, saith the Lord GOD.

34:31 And ye my flock, the flock of my pasture, are
men, and I am your God, saith the Lord GOD.